The present invention relates to a powder receiving device for receiving various types of powder transported from a truck or the like. More specifically, the present invention relates to a powder receiving device for receiving granular and/or powdered food products, feed, chemical products, and pharmaceutical products.
Powder is conventionally stored and shipped in bags or plastic containers. Alternatively, powder may be bulk shipped using a transport device such as a dump truck or a dump semi-trailer having a container with an upper section that can be opened and closed. Powder shipped in this manner arrives at a destination plant where the powder is transported with a powder air transport system installed in the plant. The powder is received by a powder receiving device (receiver) and is then stored in a silo.
Referring to FIGS. 1 and 2, a conventional system is shown for air transporting a powder from a dump truck 100 into a silo 108. Dump truck 100, arriving at a plant 101, backs into a loading area 102. A receiving hood 103, installed in loading area 102, has a powder loading opening 103a formed on a side surface. Dump truck 100 backs toward powder loading opening 103a. A container 100a is lifted and powder is loaded into receiving hood 103 from a rear door 100b. The bottom of receiving hood 103 forms a hopper-style powder outlet opening 103b. A chain conveyor 104 connects at a lower region of powder outlet opening 103b to provide lateral transfer of powder.
Powder loaded into powder loading opening 103a drops from powder outlet opening 103b through a powder feeding opening 104a of chain conveyer 104. Powder laterally transferred by chain conveyor 104 is released through a powder transfer opening 104b.
A loading hopper 105a, attached at a lower region of powder transfer opening 104b, transfers the powder vertically into a bulk conveyor 105. Powder dropped through powder transfer opening 104b is transferred upward by bulk conveyor 105. When powder reaches an uppermost section 105b of bulk conveyor 105, powder drops through a powder supplying duct 105c. 
Powder supplying duct 105c connects to a powder supply opening 106a.
The powder, laterally transferred by a chain conveyor 106, drops into a powder transfer opening 106b. A connecting pipe 107 connects powder transfer opening 106b to a ceiling 108a of silo 108. Powder stored inside silo 108 is fed through an outlet gate 109 at the bottom of a hopper 108b into a supply pipeline (not shown in the figure).
In the conventional powder supply system described above, a considerable amount of powder escapes when the powder is loaded in bulk into receiver hood 103. Powder blown out from powder loading opening 103a enters back into container 100a of dump truck 100, making dump truck 100 dirty. In addition, the escaping powder aggravates the work environment around loading area 102, requiring frequent cleaning of loading area 102.
A dust collector 110 is attached at an upper floor of plant 101. A suction pipe 111 connects the inside of receiver hood 103 with dust collector 110. Powder returns to silo 108 from an outlet side of dust collector 110 through a circulation pipe 112. A suction fan 113, disposed on an upper surface of dust collector 110, takes air in through dust collector 110 and lets the air out through an outlet pipe 114 attached to a vent opening 115 of plant 101. This conventional system restricts the escape of powder to some degree.
However, since dust collector 110 is installed at a high position, extra space is required. Also, since outside air enters receiver hood 103, the internal suction power (pressure distribution) is uneven, resulting in stagnation of air and preventing efficient dust collection. Furthermore, powder retrieved in dust collector 110 must be returned to a supply line of silo 108, allowing residual powder inside circulation pipe 112 to decompose. If dust collector 110 is used, different powders from other sources can become mixed with the desired powder, thus decreasing product value.
It is a first object of the present invention to provide a powder receiving device which results in a clean workplace where the escape and flying up of powder in a loading section is minimized.
It is a second object of the present invention is to provide a powder receiving device which prevents unevenness of pressure during dust collection, thus allowing dust to be efficiently collected.
It is a third object of the present invention is to provide a powder receiving device which prevents pressure loss in the duct piping and prevents contamination inside the duct piping.
It is a fourth object of the present invention is to provide a powder receiving device which uses an air blower that requires low suction power in the dust collector.
It is a fifth object of the present invention to provide a powder receiving device which substantially prevents noise from the dust collector.
Briefly stated, the present invention provides a powder receiving device having a loading chamber with an integral dust collector. The dust collector preferably includes at least one bag filter which filters air taken from above powder loaded into the loading chamber. The filtered air is then fed either back into the loading chamber, into a hopper where the powder is released to an external location, or out over the container from which the powder is loaded. This air flow provides for increased fluidity of the powder. The bag filter is positioned facing the loading chamber, such that when a backwash mean sends a pulse of air into the bag filter, the collected powder is dropped back into the loading chamber. The resulting powder receiving device prevents powder from escaping when powder is transferred from a container into the loading chamber. Since the powder is prevented from escaping, the powder receiving device further provides a clean workplace.
According to an embodiment of the present invention, there is provided a powder receiving device for receiving powder comprising a housing, a loading chamber within the housing for receiving the powder, a powder loading hopper attached at a bottom of the housing to direct powder from the loading chamber to an external location, a blower, the blower moving air on an air path originating inside the loading chamber, at least one bag filter in the housing in the air path, the bag filter being effective for filtering particles of the powder in the air path, and the at least one bag filter being positioned to permit the particles to fall into the powder loading hopper upon release from the bag filter.
According to another embodiment of the present invention, there is provided an integrated powder receiving device comprising a housing, a powder loading chamber in the housing, a powder loading hopper attached at a bottom of the powder loading chamber to receive powder from the housing and to direct powder to an external location, a fan drawing air from the powder loading hopper into an air path, at least one bag filter in the air path, the bag filter being of a type effective for filtering airborne particles of the powder from the air path, and the air path directed to at least one high location and one low location in the housing.
According to a further embodiment of the present invention, there is provided a powder receiving device comprising a loading chamber for conveying powder to a hopper therebelow, a blower drawing air on an air path from the loading chamber, a first air outlet from the air path, the first air outlet being close to the hopper, thereby increasing a fluidity of the powder in the hopper, whereby a flow of the powder through the hopper is improved, and a second air outlet high in the loading chamber for producing a downward flow of air toward the hopper, whereby the powder is preferentially directed toward the hopper.
The invention provides a powder receiving device wherein the dust collector is a bag filter. By using a bag filter, contamination due to adhesion of powder in internal flanges is eliminated. Thus, internally bent members can be used and flanges may project inward or outward. The result is a powder receiving device having a sleek exterior appearance which is easy to clean.
The invention also provides a powder receiving device wherein a filter is oriented toward a powder loading opening. The filter includes a plurality of bag filters disposed laterally in a row. In particular, this orientation prevents variations in suction power.
The invention also provides a powder receiving device wherein a flap is disposed at an air blowing opening of the bag filter. The flap directs air from the air blowing opening above and below a loading chamber into which powder is loaded. This air direction promotes fluidity of the powder in the loading chamber. In addition, cleaning of the device after powder is received is made easier.
The invention also provides a powder receiving device wherein an upper air blowing opening blows air flowing above the flap to below the loading chamber. The upper air blowing opening keeps the dust source (the container of the truck) near the powder loading opening clean.
The invention further provides a powder receiving device wherein a lower air blowing opening blows air flowing below the flap to above the loading chamber. This promotes fluidity of the powder.
The invention also provides a powder receiving device further including overlapping opening/closing gates. These gates protect the powder receiving operation from air currents.
The invention further provides a powder receiving device wherein a dust protection sheet is disposed on the opening/closing gate. The dust protection sheet provides further improvements in sealing the powder receiving operation from air currents.
The invention also provides a powder receiving device wherein the opening/closing gates operate by an eccentric sprocket mechanism. This mechanism allows the dust protection sheet to be smoothly folded when the opening/closing gates are closed.
The invention further provides a powder receiving device further including a sensor which detects the approach of transporting means. A control device controls the opening and closing of a door in response to a signal from the sensor. The sensor/control device combination automates the powder receiving operation.